Boolean Operators link concepts and are used to broaden or narrow your search. Briefly, here's how they work:
AND - finds results with your all search terms. AND narrows your search.
OR - finds results with any of your search terms. OR broadens your search.
NOT - finds results with only one of your search terms. NOT narrows your search.
Wildcards are used when you are unsure of a particular spelling or if there are alternate spellings of your search term. The most common wildcard symbol across databases is the "?". The wildcards work a little different within each database, but the common function looks something like this:
| If you type: | The database will return: |
| col?r | records containing color, colour, colonizer, and colorimeter |
Similar to wildcards is the truncation function. Truncation is also used when you are unsure of a spelling or only know part of a search term. The common truncation symbol across the databases is the "*". What the * does is it begins searching for any words that begin with the letters you've typed, but may end in many different ways. It looks something like this:
| If you type: | The database will return: |
| educat* | records containing educate, educates, education, educated, etc. |
| teach* | records containing teach, teacher, teachers, teaches, teaching, teachability, etc. |
Library of Congress (LOC)
The Library of Congress Classification is a system of library classification developed by the Library of Congress in the United States, which can be used for shelving books in a library. It is used by most research and academic libraries in the U.S. and several other countries. Learn how the Library of Congress classifies its subject to help you with your research.
Check out the Library of Congress Classification System
LOC Subject Headings
Subject headings are constantly being revised with the Library of Congress system. You can check out new and updated subject heading.
Subject and Genre/Form Headings
Library of Congress Subject Headings PDF Files (check out the Individual PDF Files: By Beginning Letter)